Stent of aortic valve

ABSTRACT

A stent of the aortic valve which is self-expandable and repositionable, preferably made from nitinol, consisting of two parts: the upper part and the lower part. The lower part is a mesh (1) laid out so that it creates a kind of cylinder wall on the entire height of the element. Also other shape of the mesh is acceptable, for example partially conical, or partially resembling flattened side wall of the cylinder. The upper part of the stent consists of derived from the mesh (1) upwards and arranged at equal intervals three arms (2) the height of which is slightly larger than the height of the mesh (1), a bit less than the height of the mesh (1) or equal to its height. The stent arms (2) are shaped in such a way that they form together a kind of an oval chalice bowl, and their end, peripheral part is preferably straight and also inclined to the middle.

The present application is filed under 35 U.S.C. 111(a) as acontinuation-in-part application of the parent application Ser. No.16/343,684, filed on Apr. 19, 2019, which claims priority of Polishpatent applications nos. P.419173, filed on Oct. 19, 2016, and P.423186,filed on Oct. 18, 2018, contents of each of which is being incorporatedin the present application by reference.

The subject of the invention is a stent of aortic valve, implementedtranscatheterly.

Human aortic valve is between the left ventricle of the heart andascending aorta, i.e. the first part of the aorta. It provides aunidirectional flow of blood from the left ventricle of the heart to theaorta, which is the starting point of the systemic circulation. Thevalve opens at time of a contraction of the left ventricle of the heart,when the pressure in the left ventricle exceeds the aorta pressure.Whereas in the period of a diastole of the left ventricle, when thepressure in the left ventricle drops below the aorta pressure—the valvecloses automatically.

Traditionally, a recognized treatment modality of aortic valve stenosisis surgical replacement of the aortic valve with an artificial orbiological valve. This is a method known for more than 40 years andaccording to the guidelines of the European Society of Cardiology iswithin the first class of indications. Unfortunately, this method isassociated with the necessity of surgical opening of the chest(sternotomy) and the application of cardiopulmonary bypass. The datapublished by the Society show that at the beginning of the 21st centuryone third of patients diagnosed with aortic valve stenosis was notoperated on. The reason for this is the fact that the disease is nowespecially present in older population of patients in the 6th, 7th, 8th,9th decade of life. This age group very frequently suffers fromcomorbidities. The patients are not receiving surgical treatment becauseof recognition of severe comorbidities, high surgical risk orinoperability. In 2002 Alan Cribier was first to implant an aortic valveto a patient without opening the chest and the necessity to connectcardiopulmonary bypass. This was the method currently referred to as“TAVI” (TRANSCATHETER AORTIC VALVE IMPLANTATION). The valve implanted byprof Cribier was a valve referred to as “Cribier-Edwards” valve. It wasactually a bovine valve on metal stent, implanted through the expansionof a balloon on which it was mounted. Currently the third generation oftranscatheterly implanted valves is in use: “Sapien 3”. This valveconsists of a cobaltic and chromic alloy scaffold and bovinepericardium. After the implantation it mostly provides access to thecoronary arteries and allows performance of coronarography.Nevertheless, this possibility depends on the height of the executedimplantation. This valve cannot be repositioned, which means that onceimplanted, it cannot be reimplanted or moved.

Then, a valve called “Core Valve” was placed on the market. Currentlynewer versions of this valve are available, marked “Evolut R” and“Evolut R Pro”. These are valves implementing a completely differentconcept of transcatheterly implanted valves. They are made of nitinoland are self-expandable. Additionally, “Evolut R” and “Evolut R Pro”valves can be repositioned, i.e. they can be folded in the patient'sbody—in case of improper implantation—and reimplanted. Valverepositioning is done in cases where the valve has not yet beendisconnected from the delivery system, but is already working. At thispoint you can check and make sure that it is properly located and youcan decide about its ultimate disconnection from the delivery system andthus about the final implantation. Leaflets of this biological valve aremade of porcine pericardium. Generally, however, this valve hinders theaccess to the coronary arteries due to the crown of nitinol in the shapeof a fairly dense mesh. This valve is implanted also in the way whichdoes not provide sufficient and secure location of new valve leafletsopposite the semilunar leaflets of the patient's aortic valve. Abiological valve of this design is according to the assumption sewn intothe stent supra-annularly—i.e. few millimeters over the patient's aorticvalve annulus.

Another valve, “Portico” is also a nitinol valve, self-expandable,possible to be repositioned, with a biological valve implanted at theheight of the annulus of aortic valve. Its leaflets are made of bovinepericardium. However, it prevents the free access to the coronaryarteries. This valve is implanted also in the way which does not providesufficient and secure orientation of the new valve leaflets opposite thesemilunar leaflets of the patient's aortic valve.

Another valve implanted using the “TAVI” method is “BioValve”. It iscurrently under examination. The first reports of its implantation inhumans have appeared. It is also a nitolin valve, self-expandable andpossible to be repositioned. Likewise, however, its design does notprovide free access to the coronary arteries. It is also implanted inthe way which does not provide sufficient and secure orientation of thenew valve leaflets opposite the semilunar leaflets of the patient'saortic valve. Leaflets of this biological valve are made of porcinepericardium.

A different aortic valve to be implanted using the “TAVI” method is“Accurate” valve. This is a valve in which the biological valve leafletsare made also of porcine pericardium. It is a nitinol, self-expandablevalve, but it cannot be repositioned. You cannot change its position inthe event of an abnormal implantation. Although it provides easy accessto the coronary arteries, but in practice a precise implantation is alsoa requirement for such a possibility. And indeed, too high implantationdoes not allow free access to the coronary arteries, and it happens inclinical practice. Then, unfortunately, you cannot improve its position.The valve is implanted in the way which does not provide sufficient andsecure orientation of the new valve leaflets opposite the semilunarleaflets of the patient's aortic valve.

In recent times, many new valves appeared with different, originaldesigns, such as “Direct Flow” valve which is constructed of metal-freepolyester scaffolding. Its leaflets are made also of bovine pericardium.This valve provides access to the coronary arteries, can be repositionedand is implanted in an original way.

The next known valve is “Lotus” valve. This is actually a nitinol,self-expandable, implanted in an original way valve. Its leaflets aremade of bovine pericardium. The valve theoretically provides access tothe coronary arteries and can be repositioned. Its shape and method ofimplantation is quite different from other self-expandable valves suchas “Core Valve”, “Evolut R”, “Portico” and “BioValve”.

From the American description of the invention with the applicationnumber US2014163667 is known a solution entitled “Stentless aortic valvereplacement with high radial strength”. A stentless, intravascularlyimplanted heart valve is presented there. The valve formed at the placeof implantation shows excellent resistance to crushing compared toconventional valves expanded using a balloon or based on aself-expandable stent.

From the Japanese description of the invention with the applicationnumber JP2014000417 is known a similar solution entitled “Transluminallyimplantable heart valve with formed in-place support”. The inventionsolves the problem of a need to resign from the stent and deliver thevalve in place of implantation without the help of other structures. Thedeveloped prosthetic heart valve includes: filled cuff with at least onechannel that is configured so as to create a construction that is atleast partially filled. The valve is designed so that it allows the flowin one axial direction, and blocks the flow in the other axialdirection, the opposite in relation to the first. The valve consists ofmany tissular elements which constitute its reinforcement.

From another, Polish description of the invention with the applicationnumber P-293772 (BUP date of publication 1993 Sep. 20) is known asolution entitled “Flexible stent for heart valve”. This stent iscomposed of plastic bearing element forming a homogenous structure,collar and hem material made of a homogenous piece without cuts,uniformly tight over the entire surface of the stent. Plastic bearingelement has the shape of a truncated cone or similar to a truncated conewith an apical angle at most equal to 8°. Three spread supporting armshave the top radius which is at most ⅛ of the diameter of the bearingelement at the base. On a flat base of the bearing element there arethree indentations in the axis of supporting arms with radii equal to atmost twice the top radius of the supporting arm and a height of at least1 mm. The internal diameter of the element measured at the base dependson the size of the used valve and ranges from 17 to 33 mm. A stent is astructural component that allows the implantation of natural animal andhuman valves, and, in particular, human pulmonary valve in mitral andtricuspid position.

The purpose of the invention is the development of a heart valve stent,as well as improved versions of such stent which will connect theadvantages of previously known designs, and will allow the creation of avalve which is self-expandable and can be repositioned, however, it isaffixed better than those previously known and allows access to thepatient's coronary arteries after implantation, and allows its accurateand planned positioning during implantation operation. At the same time,the purpose of the invention is not only to ensure the correctimplantation of the aortic valve (in accordance with the commissures ofthe patient and therefore providing free access to the coronaryarteries) but also to reduce the risk of damage of the cardiacconduction system, as well as to avoid an undesirable pressure of thelower tag on the conduction system.

Has been developed a stent of aortic valve that has three arms in theupper part and is self-expandable and can be repositioned and consistsof two parts: the upper part and the lower part. Wherein the lower partconsists of a mesh laid out so that it creates a kind of peripheral wallof this element. However, the upper part of the stent consists ofderived from the mesh upwards and arranged at equal intervals three armsthe height of which is slightly larger than the height of the mesh, abit less than the height of the mesh or equal to its height. The essenceof the developed stent lies in that the end, peripheral part of its armsusually is straight or curved inwards or inclined to the outside and atthe same time whole arms are:

-   -   S-shaped or    -   C-shaped or    -   straight and        at the same time are:    -   pointed straight up or    -   inclined to the middle or    -   inclined outwards,        wherein space between the arms ensures free access to patient's        coronary arteries. However, at the end of each arm an upper        valve tag is placed, and each upper tag has its corresponding        tag located at the bottom of the mesh, which is on the opposite        side of the given arm. Each lower tag is different from others        and can be seen with X-rays, allowing planned and precise        implantation of the valve, and peripheral wall of the mesh is        cylindrically shaped or almost cylindrically shaped, preferably        at least partially funnel-shaped and hourglass-shaped.

Preferably, in the developed stent of aortic valve at least its mesh ismade of material showing so-called “shape memory effect”, preferably ofnickel and titanium alloy, optimally from nitinol and/or made from wire,or constitutes a monolithic element preferably made from tube.

Preferably, the arm of the developed stent has a single or doublestructure, i.e. it consists of a single boom or two juxtaposed with eachother, possibly integrated and at least partly adjacent to each other.

Preferably, the upper valve tag resembles in shape a spherical disk orsmall, low, almost flat cylinder with rounded edges or has a shape offlat element of unique shape or is derived from the arm and constitutesits curvature and additionally, possibly has characteristic holes orpatterns.

Preferably, the mesh has at least two, preferably three or nine rows ofmesh holes, wherein preferably the holes have the shape similar to thecontour of longitudinal section of a lemon or have the shape similar tothe contour of a drop.

A stent of aortic valve that has three arms on the upper part and isself-expandable and repositionable, has two parts:

the upper part (which has three arms derived from the mesh upwards andarranged at equal intervals, the height of which is greater than theheight of the mesh, slightly less than the height of the mesh or equalto its height, wherein at the end of each arm an upper tag is placed)andthe lower part (which has a mesh distributed in such a way that itcreates a kind of peripheral wall of the element),characterized in that each upper tag (3) has its corresponding lower tag(8) wherein three upper tags (3) correspond to three lower tags (8)which are shifted by 60° from the upper tags (3). Each lower tag (8) isplaced on the contour of the lower part of the valve stent, i.e. on thelower edge (6) of membrane and—as if were in a top view—each lower tag(8) is visible halfway between the arms (2). Each lower tag (8) ispreferably different from others and can be seen with X-rays and whereinthe upper tag (3) resembles in shape a spherical disk or small, low,almost flat cylinder with rounded edges or has a shape of a flat elementof unique shape or is derived from the arm (2) and constitutes itscurvature and additionally has characteristic holes or patterns.

Another advantage of the solution in which the lower tags are shifted by60° from the upper tags (as shown in the embodiments in FIGS. 7 and 8)is that:

-   -   the tags will ensure the protection of the cardiac conduction        system against the pressure by the aortic valve stent elements,        in particular by the lower tags which ensures that the        conduction system will not be damaged and the conduction        disturbances through the conduction system will appear less        frequently; as a consequence, there will be less need for        implantation of the cardiac pacing system (pacemaker) after TAVI        (transcatheter aortic valve implantation); with this arrangement        of the lower tags, their position prevents from damage of the        cardiac conduction system resulting so far from the risk that        one of the lower tags may put pressure on the cardiac conduction        system (if it is located under arms);    -   the fact that the lower tags are shifted from the upper ones        also does not disturb in performing their basic function, i.e.        the lower tags visible under X-rays which helps in a correct        implantation of an aortic valve; known linkage of lower tags and        arms (shifted by 60° relative to each other) will help to        orientate the aortic valve in the stent space so that, after        implantation, the arms are at the place of commissures of the        patient's valve and the space between the arms provides free        access to coronary arteries; experience resulting from the        implantation of aortic valves shows that the implantation uses        several projections (the position of X-ray tube in relation to        the patient) predetermined (calculated) on the basis of analysis        of computed tomography examination with contrast; when using        several projections, the upper tags and the lower tags may be        the same, although, preferably, they may differ from each other        and may be even better distinguishable under X-rays; with the        same upper tags 3 and lower tags 8 we can learn about their        position in relation to the sinuses and commissures from their        position visible in several projections;    -   the lower tags will perform the function (thanks to their        outward curvature) of additional holding, securing the valve,        which in turn will allow high valve implantation and avoiding        the contact of the valve's elements with the cardiac conduction        system; this allows reducing the risk of need to implant a        pacemaker after TAVI due to conduction disturbances.

The subject of the invention is shown in the embodiment in drawings,where:

FIG. 1—shows the side view of the stent of aortic valve with nine rowsof holes,

FIG. 2—shows the side view of the stent of aortic valve with five rowsof holes,

FIG. 3—shows the side view of the stent of aortic valve with three rowsof holes, with drawn membrane and leaflets of the aortic valve,

FIG. 4—shows the side view of the stent of aortic valve with three rowsof holes, of slightly different shape with drawn membrane and leafletsof the aortic valve,

FIG. 5—shows the top view of the stent with drawn not fully closedleaflets of the aortic valve,

FIG. 6—shows the diagonal lower view of the stent with visible lowertags and

FIG. 7—shows the axonometry of the stent of aortic valve with lower tagsshifted by 60° from the upper tags and

FIG. 8—shows the top view of the stent of aortic valve with lower tagsshifted by 60° from the upper tags/arms.

The stent of a self-expandable, possible to be repositioned aortic valveimplanted transcatheterly provides a flexible framework which consistsof two parts: the upper part and the lower part. The lower part is amesh 1 laid out so that it creates a kind of cylinder wall or almost acylinder wall on the entire height of the element. Wherein the mesh 1can be flattened cylinder-shaped or partly funnel-shaped orhourglass-shaped.

Planning a necessary degree of oversizing of an implanted valve inrelation to the size (circumference or area) of the patient's aorticvalve annulus is possible, in particular in case of a cylinder-shapedstent. This is enabled through earlier determination of the patient'ssize of aortic valve annulus and known and appropriately matched size ofthe lower part of the stent.

Oversizing of the valve is the % by which the circumference or surfacearea of the base of the stent are greater from the circumference orsurface area indicated by the patient's aortic valve annulus. Adjustmentof those values and use of the stent with appropriately matchedoversizing is necessary due to the fact that, in addition to the shapeof the stent, it is one of the mechanisms for maintaining the valve inthe place in which it was implanted. Oversizing results also in closeadjustment of the stent to the patient's aortic annulus after theremoval of the delivery system elements.

However, the upper part of the stent consists of derived from the mesh 1upwards and arranged at equal intervals three arms 2 the height of whichis slightly larger than the height of the mesh 1, a bit less than theheight of the mesh 1 or equal to its height. The arms 2 are shaped insuch a way that together they make up a kind of contour of an ovalchalice bowl. The end, peripheral part of each of the arms 2 is usuallystraight or curved inwards or inclined outwards. At the same time, thewhole arms 2 are:

-   -   S-shaped or    -   C-shaped or    -   straight and        at the same time are:    -   pointed straight up or    -   inclined to the middle or    -   inclined outwards.

The arm 2 can have a single or double structure, i.e. it may consist ofa single boom or two juxtaposed with each other, or integrated or atleast partly adjacent to each other. When they are made from a materialused for the mesh 1 then they can be derived directly from the mesh 1.

The free space between the arms 2 provides easy access after the valveimplantation to the patient's coronary arteries from the side of theaorta bulb. At the end of each arm 2 the upper valve tag 3 is placed,the shape of which typically resembles a small, low, almost flatcylinder with rounded edges. Equally favorable, it may also have a flatelement shape of unique shape which preferably, has characteristic andcharacterizing it holes or patterns. Therefore it may have a throughhole in the middle, and may be, for example, of a spherical disk shape.It may be derived from the arm 2 and may, for example, be formed as aresult of curling up the material from which the arm 2 is made or fromwhich the mesh 1 is made. The upper tag 3 allows you to anchor the stentin the delivery system, used for the implantation of the valve. It is anelement for fixing the stent to the delivery system, and at the sametime its shape provides easy disconnection of the valve from thedelivery system at time of the final valve implantation.

The arms 2 designed in such a way with the upper tags 3 of the arms 2supporting it—ease embedding of the valve in the delivery system andenable holding them by this system in the case of a necessity toreposition the valve.

A sealing membrane 4 is sewn into the described stent or more preciselyinto its lower part. The membrane is integrated, e.g. sewn at the topwith the valve leaflets 5. These elements, i.e. the membrane 4 andleaflets 5 may be made of the same material. While usually the leaflets5 are made of bovine or porcine pericardium or other biological materialor synthetic material. The area between the lower edge of the membrane 6and the upper edge of the membrane 4 (stretching along the base of thearms 2)—is a zone of sealing and adhesion of the implanted valve to thepatient's aortic valve annulus. However, the lower parts 7 of theleaflets may be located, i.e. attached to the membrane 4 at different,preplanned height. It seems that it is more favorable to implant thevalve slightly higher over the annulus of the patient's anatomicalaortic valve (supra-annularly). Each of the three leaflets 5 of thevalve is always sewn between the arms 2 because then when the leaflets 5of the implanted aortic valve are opposite the leaflets of the patient'saortic valve, the space between the arms 2 will allow free access to thecoronary arteries.

The majority of patients has the aortic valve annulus with an ovalshape. Then, even if the implanted valve takes an oval shape at thebottom, at the top it has a nearly circular or round shape and functionscorrectly, i.e. it enables the proper closure of its leaflets 5.

An optimal place for the leaflets 5 to be sewn will be established as aresult of the carried out further research and work. It is assumed inthe embodiment, that the lower edge 6 of the implanted valve—measuredfrom the base without the lower tags 8, i.e. from the lower tops of meshholes constituting the lowest, first row 9 of the mesh holes 1—it isdistant from the lower edge 7 of the leaflet 5 of the aortic valvepreferably by 12 mm. It can be otherwise, the optimal distance of theseelements will also be determined in the course of further research andwork.

Each upper tag 3 corresponds to the located at the bottom of mesh 1,i.e. on the opposite side and under a given arm 2 lower tag 8. The lowertags 8 are usually placed at the same angle on the outside of thecylindrical or almost cylindrical mesh 1 and are, as they were, itsextension. They may be ring-shaped with different fillings, or they areextended and are usually derived from the material used for the mesh 1or can be made of a different material and only attached to the mesh 1.

It is vital that each lower tag 8 is different from other lower tags 8.They are at the same time visible and recognizable in radiation duringx-ray fluoroscopy (that is, the radiological imaging performed at thetime of valve implantation), and owing to this they are helpful in theprocess of determining and selecting the appropriate valve position. Thelower tags 8 allow at the time of implantation for such orientation ofthe stent in the space obtained by twisting the delivery system so thatall the leaflets 5 of the aortic valve are exactly opposite theircounterparts, that is, the leaflets of the patient's aortic valve. Thislater ensures the above described free access—when it is needed—to thecoronary arteries through the space between the arms 2 of the stent. Thedescribed design allows precise implantation of the stent.

The lower tags 8 are at the same time additional reinforcement andprotection of the valve, preventing movement in the direction of theaorta during contraction of the left ventricle of the heart.

The mesh 1 has at least two, preferably three rows of holes, but equallypreferable more rows of holes, i.e. 9 or other quantity (as shown forexample in FIG. 1 and FIG. 2). The mesh 1 is cylindrically-shaped oralmost cylindrically-shaped primarily in that part of the mesh 1 whichis the zone of adhesion to the patient's aortic valve annulus, coveringat least the lowest, first row 9 of holes.

One row of the mesh 1 may consist of any number of holes, favorably atleast nine. Their quantity usually represents a multiple of the figurethree.

In the embodiment (FIG. 3)—mesh holes in the lowest, first row 9 havethe shape similar to the contour of longitudinal section of a lemon, andthe next row of holes have the shape similar to the contour of a drop,whereas the lower tags 8 are extended. However, holes can have any shapeto enable the stent to be folded.

Both the mesh 1 and arms 2 derived from it are made of material showingso-called “shape memory effect”, ensuring the possibility of folding andexpanding of the valve. Such material can be nickel and titanium alloy,for example nitinol. The elements can be made of nitinol wire. The stentalso can be a monolithic element made from nitinol tube out of which thewhole stent is laser cut, for example. The mesh 1 and similarly arms 2also can be made from other material.

The developed stent with the membrane 4 sewn therein to and withseparated in its upper part leaflets 5 constitute a valve prepared to beintroduced into the heart through the delivery system. Before the valveis delivered, it is compressed to the dimensions allowing putting acover thereon. However, its implantation is based on that at the timethe valve is at the height of the patient's aortic annulus, the cover isbeing slid. Then the valve expands and is partially implanted whichalready allows for the functioning of the valve. After establishing andverifying the valve position as a result of:

-   -   conducted echocardiography and/or    -   administering contrast to the aorta bulb during aortography        and/or in any other way,    -   if this position is correct, further sliding of the cover from        the stent and final disconnection of the valve from the delivery        system is made. In the event of an incorrect valve position it        can be repositioned after reapplying the cover on the stent        (before its ultimate disconnection). At the beginning of        implantation the cover is slid only so that the lower tags 8 are        visible.

Today, the vast majority of patients eligible for transcatheter aorticvalve implantation is treated with computed tomography test. On thebasis of this test it is possible to priorly determine the x-ray tubeangles relative to the hemodynamic table on which the patient liesduring the valve implantation. If in this position of the x-ray tubethree lower tags 8 are visible in firm, intended placement, ensuringcorrect setting of the leaflets 5 of the aortic valve opposite thepatient's valve leaflets—the valve is implanted. That is why, thedeveloped design of the stent in question is so helpful and importantfor the proper conduct of implantation of the aortic valve.

In the embodiment (FIGS. 7 and 8)—each upper tag 3 corresponds to alower tag 8, wherein each lower tag 8 is shifted by 60° from itscorresponding upper tag 3. Each lower tag (8) is on the contour of thelower part of the valve stent, as if were halfway between the arms (2).Wherein, each lower tag 8 is preferably different from others and can beseen with X-rays and the upper tag 3 resembles in shape a spherical diskor small, low, almost flat cylinder with rounded edges or has a shape ofa flat element of unique shape. The upper tag 3 may also be derived fromthe arm 2 and constitute its curvature and additionally havecharacteristic holes or patterns.

In the embodiment shown in FIGS. 7 and 8, the lower tags 8 during theimplantation of the valve on the stent are at the level of the bottom ofthe aortic bulb sinuses (in the abovementioned embodiments—shown indrawings FIGS. 1 to 4 and FIG. 6—the lower tags 8 were in the places ofcommissures/arms 2, looking at the valve from above or below). On theother hand, the arms 2 will be located in the same place as they werebefore (in the previous embodiments, i.e. in the FIGS. 1 to 6),therefore, in the place of commissures, i.e. the places of junction ofthe patient's aortic valve leaflets and the new valve. The space betweenthe arms 2 will provide free access to the coronary arteries.

Thanks to the location indicated in the embodiments shown in FIGS. 7 and8, the lower tags 8:

-   -   ensure the protection of the cardiac conduction system against        the pressure by the aortic valve stent elements, in particular        by the lower tags 8 which ensures that the conduction system        will not be damaged and conduction disturbances through the        conduction system will appear less frequently; as a consequence,        there will be less need for implantation of the cardiac pacing        system (pacemaker) after TAVI (transcatheter aortic valve        implantation); with this arrangement of the lower tags 8, their        position prevents from damage of the cardiac conduction system        resulting from the risk that one of the lower tags 8 may put        pressure on the cardiac conduction system (if it is located        under upper arms 2) and cause conduction disturbances:        atrioventricular blocks and, as a consequence, some patients may        need an implantation of a pacing system after surgery;    -   perform their basic function, which is to assist in a correct        implantation of an aortic valve; the fixed linkage of lower tags        8 and arms 2 (shifted by 60° relative to each other) will help        to orientate the aortic valve in the stent space so that, after        implantation, the arms 2 are at the place of commissures of the        patient's valve and the space between the arms 2 provides free        access to coronary arteries; experience resulting from the        implantation of aortic valves shows that the implantation uses        several projections (the position of X-ray tube in relation to        the patient) predetermined (calculated) on the basis of analysis        of computed tomography examination with contrast; when using        several projections, the upper tags 3 and the lower tags 8 may        be the same, although, preferably, they may differ from each        other and may be even better distinguishable under X-rays; with        the same upper tags 3 and lower tags 8 we can learn about their        position in relation to the sinuses and commissures from their        position visible in several projections;    -   the lower tags 8 will perform the function (thanks to their        outward curvature) of additional holding, securing the valve,        which in turn will allow high valve implantation and avoiding        the contact of the valve's elements with the cardiac conduction        system; this allows reducing the risk of need to implant a        pacemaker after TAVI due to conduction disturbances.

The valve leaflets 5 may be positioned not only supra-annularly but alsointricately.

LIST OF ELEMENTS

-   -   1. mesh;    -   2. arm;    -   3. upper tag;    -   4. membrane;    -   5. leaflet (of valve);    -   6. lower edge (of membrane);    -   7. lower part (of leaflet);    -   8. lower tag;    -   9. first row (of mesh holes).

1. A stent of aortic valve comprising three arms on the upper part andis self-expandable and repositionable, having two parts: the upper partand the lower part, wherein the lower part has a mesh distributed insuch a way that it creates a kind of peripheral wall of the element, andthe upper part of the stent has three arms derived from the mesh upwardsand arranged at equal intervals the height of which is greater than theheight of the mesh, slightly less than the height of the mesh or equalto its height, wherein at the end of each arm an upper tag is placedcharacterized in that each upper tag (3) has its corresponding lower tag(8) located at the bottom of the mesh (1), that is on the opposite sideand below the given arm (2), wherein each lower tag (8) is differentfrom others and can be seen with X-rays, allowing planned and preciseimplantation of the valve and wherein the upper valve tag (3) resemblesin shape a spherical disk or small, low, almost flat cylinder withrounded edges or has a shape of a flat element of unique shape or isderived from the arm (2) and constitutes its curvature and additionallyhas characteristic holes or patterns.
 2. The stent of the aortic valveaccording to claim 1, characterized in that at least the mesh (1) ismade of material showing “shape memory effect”, of nickel and titaniumalloy, from nitinol and/or made from wire, or constitutes a monolithicelement preferably made from tube.
 3. The stent of the aortic valveaccording to the claim 1, characterized in that the arm (2) has a singleor double structure, consisting of a single boom or two juxtaposed witheach other, integrated or at least partially adjacent to each other. 4.The stent of the aortic valve according to claim 1, characterized inthat the mesh (1) has at least two, three or nine rows of holes, whereinthe holes have the shape similar to the contour of longitudinal sectionof a lemon or have the shape similar to the contour of a drop.
 5. Thestent of aortic valve according to claim 1, wherein the stent has threearms on the upper part and is self-expandable and repositionable,consists of two parts: the upper part and the lower part, wherein thelower part has a mesh distributed in such a way that it creates a kindof peripheral wall of the element, and the upper part of the stent hasthree arms derived from the mesh upwards and arranged at equal intervalsthe height of which is greater than the height of the mesh, slightlyless than the height of the mesh or equal to its height, wherein at theend of each arm an upper valve tag is placed, characterized in that eachupper tag (3) has its corresponding lower tag (8) located at the bottomof the mesh (1), that is on the opposite side and below the given arm(2), and wherein each lower tag (8) is different from others and can beseen with X-rays, allowing planned and precise implantation of the valveand wherein, the upper valve tag (3) resembles in shape a spherical diskor small, low, almost flat cylinder with rounded edges or has a shape ofa flat element of unique shape or is derived from the arm (2) andconstitutes its curvature and additionally has characteristic holes orpatterns.
 6. A stent of aortic valve comprising three arms on the upperpart and is self-expandable and repositionable, having two parts: theupper part and the lower part, wherein the lower part has a meshdistributed in such a way that it creates a kind of peripheral wall ofthe element, and the upper part of the stent has three arms derived fromthe mesh upwards and arranged at equal intervals, the height of which isgreater than the height of the mesh, slightly less than the height ofthe mesh or equal to its height, wherein at the end of each arm an uppertag is placed, characterized in that each upper tag (3) has itscorresponding lower tag (8) wherein three upper tags (3) correspond tothree lower tags (8) which are shifted by 60° from the upper tags (3)and each lower tag (8) is placed on the contour of the lower part of thevalve stent, i.e. on the lower edge (6) of membrane and—as if were in atop view—each lower tag (8) is visible halfway between the arms (2),wherein each lower tag (8) is preferably different from others and canbe seen with X-rays and wherein the upper tag (3) resembles in shape aspherical disk or small, low, almost flat cylinder with rounded edges orhas a shape of a flat element of unique shape or is derived from the arm(2) and constitutes its curvature and additionally has characteristicholes or patterns.